Keyboard having magnet-actuated switches or sensors

Abstract

A text input device having a keyboard with magnet-actuated switches or magnetoelectric sensors, and a stylus with a magnet at the tip. Each key of the keyboard has a reed switch. A key is selected by moving the stylus magnet near to the selected key and switch. The magnet actuated switch closes due to the magnetic field, and the low resistance state of the switch is detected by a microprocessor. The switches can be connected in a matrix array. In an alternative embodiment, the switches are replaced with magnetoelectric sensors having mechanically coupled magnetostrictive and piezoelectric materials. The present keyboard is small and low power, and is well suited for use in portable electronic devices. The keyboard does not require pressing of the stylus against the keyboard, which facilitates fast typing and reduces user fatigue.

Description

RELATED APPLICATIONS [0001] The present application claims the benefit of priority from copending provisional application 60 / 674,376, filed on Apr. 22, 2005.FIELD OF THE INVENTION [0002] The present invention relates generally to text input devices for portable electronic devices and computers. More specifically, the present invention relates to a miniature keyboard having magnetic switches or magnetoelectric sensors. The keys are activated using a stylus having a magnet at its tip. BACKGROUND OF THE INVENTION [0003] Portable electronic devices such as cell phones, personal digital assistant devices (PDAs), portable email devices and the like often require text input. Text input is necessary for instant messaging and address entry on cell phones, and for portable email devices, for example. However, portable electronic devices are often too small for a practical, full function keyboard with 26-30 keys. Very small keys cannot be selected with the fingers. Also, keys that require pres...

AI Technical Summary

Benefits of technology

[0010] Also preferably, the strength of the stylus magnet and sensitivity of the switches are selected such that only one switch is caused to change state when the stylus magnet is disposed on a selected key.

[0011] The keyboard of the present invention is particularly well suited for use in small portable electronic devices such as cell phones, PDAs and the like.

Problems solved by technology

However, portable electronic devices are often too small for a practical, full function keyboard with 26-30 keys.

Very small keys cannot be selected with the fingers.

Also, keys that require pressure can cause repetitive stress injury in users that use the keyboard for hours a day.

However, pressing the keys with a stylus greatly slows text entry and is annoying for some users.

However, all these methods are bulky, expensive, fragile or annoying to use.

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